Originally posted by Doctor Octopus
Practice...I went from a 5 diagnostic to a 13-15 on April 2003.
Make sure you are frequently summarizing in your mind what you just read. Actively reading for structure and purpose will help you to better grasp the main points.
Everytime I read an example I wrote "ex" next to it. Everytime I saw evidence offered to support an argument, I wrote "ev" next to it. You must come up with a way to very quickly locate the relative information in the passage that you need to answer the question. All correct answers will be supported by the passage.
Most importantly, do as many practice tests and passages as you can.